How to Store Cannabis Seeds

Knowing how to store cannabis seeds properly, is important for most indoor growers. You may start of with just a couple of seeds, but it will soon mount into a collection, and they should be stored properly, to increase their chances of still being viable.

When you buy cannabis seeds from many online seed banks, you will on most occasions be given free cannabis seeds. You may also buy more seed of your favourite strain than you need, and plan to use some of them for a future grow.

If you do not store your cannabis seeds properly, they can die, and you will not be able to germinate them. In this guide we will explain how to store your cannabis seeds, so your seeds will stay viable for many years.

If you any questions about long term storage of cannabis seeds, that aren’t covered here, feel free to ask for help in our cannabis growers forum


The Best Way to Store Cannabis Seeds

Cannabis seeds, are small, roundish shaped seeds, that are usually brown, with a few dark tiger stripes on them. Inside that tiny seed, can be the genetics to some of the best cannabis strains in the world.

Sometimes, you have more seeds than you need, and you would like to store them for a future grow. If stored correctly, cannabis seeds can last for decades, and still be viable.

First off, when storing cannabis seeds, they need to be in the right sort of containers.

Containers for Storing Cannabis Seeds

Choosing the right containers for storing cannabis seeds is important. It is easy for seeds to become damaged, and though most seed banks send their seeds in good strong packaging, some don’t.

Lets say, you buy ten seeds, but only need to germinate four. Six of your seed will need to be stored safely, so you can grow them in the future. The best containers are airtight, light proof and solid.

The best containers you can use, for small amounts of cannabis seeds, are seed tubes.

Seed Tubes for Cannabis Seeds

how to store cannabis seeds

These 1.5ml Test Tubes are perfect for storing seeds. They are airtight, solid, and the perfect size for up to ten seeds.

You can buy these in bulk, 50 -100 at a time for very cheap. Using these to store your cannabis seeds, will help keep the humidity, and temperature inside the tube at a stable level.

There is also space in the tube for some cotton wool, and desiccants, which is a great way keep humidity at optimal levels.

Zip Lock Bags

If you are going to store your seed as part of a bigger collection, in a container with more seeds, it is fine to use zip lock bags. As long as they are airtight, they will do fine.

Do not use zip lock bags that have been used for other things. You should buy new bags, that are fresh and clean. Fungal spores can kill your seeds, and they are everywhere! This is another reason why keeping temps and humidity low is important.

To minimise the risk of your seeds been contaminated by mould or fungus, always use clean equipment!


As long as the container is:

Stored in the right conditions

You can store cannabis seeds for years!

Temperature for Storing Cannabis Seeds

Cannabis seed can be stored at a variety of temperatures. They might be small, but there are resistant and hardy!

Though the best temperature for storing cannabis seeds is around 5°c, cannabis seed can be kept at different temperatures and still be viable.

You can store your cannabis seeds in a dark place, at room temperature with very few problems for up to a year. But, if you intend to store cannabis seeds for a longer period of time, then storing them in a refrigerator is the best approach.

Storing Seeds at Room Temperature

For small seed collections, or for storing just a few cannabis seeds, buying a fridge can seem excessive. If you plan to use your seeds within a year, storing them in a dark cupboard, in an airtight container will work fine.

Temperature fluctuations will cause your seeds to lose viability. So be careful not to store them in a place where temperatures change often such as a kitchen, or near radiators and heating appliances.

Do not disturb your seeds unless you’re going to plant them, temperature light, and humidity fluctuations can confuse the seeds, and make them waste what little energy they have thinking they are ok to germinate.

Storing Cannabis Seeds in a Fridge


To increase the longevity of your cannabis seeds, you can store them in a fridge.

Storing cannabis seeds in a fridge is an easy way to give them a cool, dark, stable environment.

This is said to keep them viable for anything up to five years, maybe even longer.

You will not need a big fridge, a 4L mini fridge should be fine. It is important not to disturb them unless you need to. Temperature fluctuations will damage the seed, so once in the fridge, leave them there until you plan to germinate them.

Can you Freezing Cannabis Seeds

Like many things in the art of growing cannabis, this is a subject that is up for debate. And from what studies have shown, it is possible to freeze cannabis seeds and keep them viable, but it has to be done correctly.

To freeze cannabis seeds, you need specialist equipment, that most growers do not have. So it is not advised that you freeze them. You can not freeze cannabis seeds in a regular freezer, without taking the risk of killing them.

Some seeds can be frozen, and they will still germinate, but their genetics may have been damaged. This might be ok when you have hundreds of seeds to store, and can risk losing some, but not good for small collections.

If you do freeze them, you can increase the chances of them germinating, by removing them from the freezer and letting them sit at room temperature for 24 hours, before trying to germinate them. This will give them a chance to fully thaw out before the germination process begins.

Never refreeze a seed after it has defrosted.

It is common consensus amongst growers, that if a seed has been frozen and defrosted, do not refreeze it as this will certainly kill it.

Humidity for Storing Cannabis Seeds

When a cannabis seed receives enough moisture, it will begin to germinate. During storage of course we want to prevent this, so keeping humidity low is prefered.

Not too dry though, a seed is still a living thing, it is just laying dormant until the conditions are right for germination. A little moisture in the air is still needed.

The Best Humidity for Seed Storage

When a cannabis seed is in storage, the humidity should not exceed 10%, and if you achieve levels below 5% you can massively increase the lifespan of your seed.

High humidity will not only offer you seed ideal conditions to germinate, but it may also encourage mould and fungal spores to grow. So keeping humidity down is important to the longevity of your seeds.

It can be hard to monitor humidity in small containers. But, it is a good idea to add some “Desiccants” to the container your seeds are stored in.


desiccant is a hygroscopic substance that is used to induce or sustains a state of dryness (desiccation) in its vicinity; it is the opposite of a humectant. Commonly encountered pre-packaged desiccants are solids that absorb water

To put it simply, a desiccant, is something that is going to remove moisture from the air. There are a number of things you can use as a desiccant, but the 2 most common are rice, and silicone balls:


Rice will pull in moisture from the air around it.

Place your seeds into a suitable container, like a 1.5ml test tube, and then, insert a rolling cigarette filter or small piece of cotton wool. On top of this, place a couple of grains of rice, and close the lid.

You can also have grains of rice mixed with the seeds in their containers. But be careful to use clean rice, to reduce the risk of mould or fungus growing inside the tubes with the seeds.

Silicone Balls


By taking a few silicone balls, and adding them to the container holding your seeds, you can keep humidity low, and increase their lifespan.

Use a tube, and place your seeds inside, and use either a small piece of cotton wool, or a cigarette filter, and place it over the top of the seeds in the tube.

Then, place just a couple of these balls into the tube on top of the cotton wool, and store your seeds in the fridge. You can easily see your seeds last for over five years in these conditions.

Keeping Seeds in the Dark

There are three main things cannabis seeds need to germinate and grow into a seedling, warmth, moisture, and light.

When storing cannabis seeds, you need to prevent the seeds from thinking it is going to germinate. By keeping temperature and humidity low, the seed will lay dormant, but light can also have an effect on them.

Always keep your seeds in the dark. The idea is to trick the seed to thinking it is underground during winter time. This way it will lay dormant until it feels conditions change, whether its light, temperatures, or humidity levels in the air.

How Long Can Cannabis Seeds be Stored

Under the right conditions, who knows! Seeds can germinate after decades, maybe even centuries after laying dormant.

A plant called ” Silene stenophylla ” was brought back to life after 32 thousand years after some of its seeds were germinated. Seeds are amazing things, and as long as they are looked after, they will last you a long time.

If you keep your seeds at 4-5°c, humidity below 5%, and also keep them in the dark, they will be viable for decades.

Thanks for reading! You can find more information on anything related to growing in our cannabis grow guides. All of our guides are written by experienced growers, and members of our cannabis growers forum. If you have any questions, sign up. It is free, and we are always happy to help!

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